Opportunistic Hybrid Routing Protocol for Acoustic-Radio Cooperative Networks

The ocean contains abundant resources and has high-scientific and economic values. Increasing underwater communication scenarios stimulates many research efforts on underwater wireless ad hoc networks. Underwater acoustic communication technology supports medium to long-range wireless communication. However, it suffers from low-transmission data rates and long link delays. This article introduces an acoustic-radio cooperation network (ARCNet) model for more efficient maritime information transmission. Under this ARCNet, we propose a new radio-acoustic opportunistic hybrid (RAOH) routing protocol composed of a neighbor discovery mechanism and a hybrid routing strategy. In the neighbor discovery stage, we explore the surface radio links to aid in selecting the shortest delay path between an underwater node and the surface nodes. In the route establishment stage, we combine the advantages of opportunistic routing and on-demand routing and design an opportunistic hybrid routing strategy, which improves the success rate of data forwarding and reduces the time spent on route establishment. Simulation results show that the proposed RAOH protocol outperforms traditional terrestrial and underwater routing strategies in routing response speed, packer delivery rate, throughput, end-to-end delay, and energy efficiency.